Improvement in furnaces for steam-boilers



I. g. c. SEARLE. FURNACES FOR STEAM-BOILERS. No. 175,510. Patented March 28,1876.

rrnn STATES ATEN'I IMPROVEMENT IN FURNACES FOR STEAM-BOILERS.

Specification forming part of Letters Patent No. 175,5 10, dated March 28,1876; application filed 'March 17, 1876.

To all whom it may concern Be it known that I, JOHN Q. (J. SEARLE, of

Cincinnati, Hamilton county, State of Ohio, have invented certain Improvements in Steam- Boilers, of which the following is a specification The main object of my invention is the effectual and economical consumption of fuel in steam-boilers-an object which Iatta-in by so combining a partition in the fire-place with a depression in the grate that the products of combustion must, before reaching the fines of the boiler, pass through a mass of incandescent fuel lodged in the said depression, as explained hereafter.

The accompanying drawing illustrates my invention as applied to a boiler of the locomotive type.

Figure 1 is a vertical section of the fire-box end of the boiler with my improvements; Fig. 2, a transverse vertical section on the line 1 2; and Figs. 3 and 4, detached views, illustratin g parts of my invention.

A is the outer shell of the body of the boiler; B the fire-box; E, the tube-sheet, and F the grate. On the opposite sides of the fire-box, at a short distance from the tube-sheet, are arranged hollow projecting ribs a a, the interior of each rib being" in free communication with the adjoining water-space. Each hollow projection has flanges b b for supporting the removable water-back G, and is connected to the same by pipes H, which are so bent or otherwise arranged that the said waterback can expand and contract without any deteriorating efl'ect on the joints of the pipes. As a further means of securing the waterback to its place I employ studs 6, which screw into the outer shell of the boiler and pass through tubular stays f, the point of eachscrew fitting into a recess in the edge of the water-back, The two feed-pipes J J pass through thimbles fin the water-leg K, and are connected to the water-back at or near the lower portion of the same, the feed-water being thus forced directly into the said waterback, whence it passes through the pipes H H into the water-spaces of the fire-box. When the water-back has to be removed for the purpose of gaining access to the flues all that is necessary is to uncouple the feed-pipes J and circulating-pipes H, and withdraw the screwstuds 6, when the said water-back can be removed from its bearings on the flanges b. A partition of fire-clay or other refractory material, of the same shape and occupying the same position as the water-back, may be sub stituted for the latter, which, however, I prefer in all cases. The upper portion of the partition consists of a damper, L, and plate 01, the damper being so hinged to the fire-box that it can be moved outward to the position shown by dotted lines, when it is desirable for a portion of the products of combustion to pass over the Water-back. The grate F is continued in a horizontal position to the point or, where it meets the inclined or curved grate F and to the lower end of the latter is hinged.

the tilting grate F these two grates constituting the depression through which, and through the fuel lodged therein, the products of combustion must pass before they reach the fines of the boiler. As the air has free access through the grate F and F to the depressed mass of fuel the latter must burn fiercely, and the products of the combustion of the fuel on the grate F must, on passing through the depressed fuel, be thoroughly ignited and pass in the form of a flame of intense heat through the throat N, between the inclined top 9 of the water-leg K and the lower edge of the water-back.

In locomotive-boilers it is essential to promote the combustion of the depressed fuel by a forced blast, which I prefer to produce by means of steam-jets, in the manner shown in the drawing, where M represents a pipe to which air has free access, and which has noz zles w directed toward the grate F and to the entrance of the throat N. A steam-pipe, m, communicating with the steam-space of the boiler, is contained within the air-pipe M, and is so perforated that a jet of steam is projected into each nozzle w, from which air and steam combined are consequently projected through the grate F. I also prefer in the case of locomotive-boilers to force air through the grate F at the front of the same, for which purpose I arrange beneath the grate two inclined plates, 25 t, converging toward the top, where there is a narrow opening, a perforated steam-pipe, q, being contained between the Felon plates,.so that jets-0f steam will be projected H 'fire-box or fuel-chamber, the front of which depressed grate is open, with --a partition, byf

which the products of combustion are compelled to pass through the fuel on said grate,; substantially as set forth. 7

2. The combination of the depressed grate,

.theipartition above-thesame, and the throat N with devices for forcing air into the fuel contained on the said depressed grate and toward the throat N, asspecified.

3. The removable water-back Gr, adapted to the fire box, in combination with feed-pipes J J and circulating-pipes H H.

In testimony whereof Ihave signed my name to this specification'in the presence of two subscribing witnesses.

JOHN Q. o. "SEARLE.

Witnesses:

JAMES L. SKIDMORE, HUBERT HowsoN. 

